1. Field of the Invention
The present invention relates to an image transfer apparatus used in a high-resolution printer for pressure-sensitive and heat-sensitive recording of an image on a recording sheet, and more particularly for recording the image by locally pressing and selectively heating recording material that includes capsules.
2. Description of the Related Art
A printing solution is known that includes fine capsules, such as micro-capsules, filled with heat-sensitive color developing dye or ink for high-resolution printing in a high-resolution color printer. A recording sheet consists of a base sheet with a layer of the micro-capsules covering the base sheet. The layer of micro-capsules includes a plurality of types of micro-capsules, each type corresponding to a specific color ink or dye, which is seeped from the micro-capsule onto the recording sheet when the corresponding micro-capsule is heated to a predetermined temperature. The predetermined temperature varies dependent on the type of micro-capsule. Each seeped color ink or dye is developed and fixed by light of a predetermined wavelength, which also varies depending on the type of micro-capsule. Therefore, each type of micro-capsule seeps a predetermined color ink or dye when heated to the predetermined temperature, and the seeped color ink or dye is developed and fixed on the recording sheet by irradiation with the light of the specific wavelength. Thus, color development of a full-color image, to be recorded on a recording sheet, can be controlled through selection of the micro-capsules to seep the dye or ink, which occurs through control of localized heating and irradiation with a specific wavelength of light.
The recording process utilizing the recording sheet with the layer of the micro-capsules is complicated and time-consuming because the localized heating and light irradiation must be repeatedly executed in order to develop and fix a plurality of colors. When the recording sheet is a normal sheet of plain paper, it becomes difficult to record a high-resolution image on the sheet, because the normal paper usually has an uneven printing surface.
Therefore, an object of the present invention is to provide a pressure-sensitive and heat-sensitive image transfer apparatus for easily recording a full-color high-resolution image on a recording sheet through controlled localized pressure and temperature application, regardless of a surface condition of the recording sheet.
An image transfer apparatus according to the present invention comprises an ink transfer unit that includes a layer of micro-capsules containing dye, each micro-capsule disposed in the layer of micro-capsules exhibits a temperature/pressure characteristic such that, when each micro-capsule is squashed under a corresponding predetermined pressure at a corresponding predetermined temperature, dye seeps from the squashed micro-capsule and transfers to a surface of a recording sheet. A pressure application unit is also included that locally applies the corresponding predetermined pressure to the micro-capsule layer, and a heat application unit is included that selectively and locally heats the micro-capsule layer to the corresponding predetermined temperature. A pre-coating unit that pre-coats a material on the surface of recording sheet prior to transfer of dye is also included, wherein a degree of roughness of the surface of the recording sheet is diminished due to the material, such that the transferred dye is accurately fixed to the surface as the image.
Preferably, the resin of the shell wall is a shape memory resin, which exhibits a glass-transition temperature corresponding to the corresponding predetermined temperature, and the shape memory resin of the shell wall comprises a predetermined thickness.
Preferably, the image transfer apparatus includes an ink transfer storage unit that stores the ink transfer unit, and a holder that holds the ink transfer unit and the pre-coating unit. Also preferably, the image transfer apparatus includes an ink transfer storage unit that stores the ink transfer unit and the pre-coating unit, and a holder that holds the ink transfer storage unit. The pre-coating material may be a liquid or a film fixable to the surface of the recording sheet.
Further, the image transfer apparatus may include an over-coating unit that over-coats a material on the surface of the recording sheet subsequent to transfer of the dye, wherein transferred dye is permanently fixed and protected on the surface. Furthermore, the over-coating material protects the transferred dye against at least one of damaging electromagnetic radiation, oxidation, discoloration and fading.
An image transfer apparatus according to the present invention comprises a conveyor unit that intermittantly transports a recording sheet in a transport direction; a recording head that records the image line by line on a surface of the recording sheet by moving in a recording direction substantially perpendicular to the transport direction. The recording head includes an ink-transfer ribbon that comprises a base member and a layer of micro-capsules, coated over the base member, that contains a plurality of micro-capsules filled with dye, each micro-capsule of the plurality of micro-capsules exhibits a temperature/pressure characteristic such that, when each micro-capsule is squashed under a corresponding predetermined pressure at a corresponding predetermined temperature, the dye discharges from the squashed micro-capsule and transfers to the surface of the recording sheet. The image transfer apparatus further comprises a temperature application unit that selectively and locally heats the layer of micro-capsules to the corresponding predetermined temperature, a pressure application unit that locally applies the corresponding predetermined pressure to the layer of micro-capsules, and a pre-coating material container, positioned downstream of the recording direction, that pre-coats a material on the surface of the recording sheet prior to the discharge of the dye, wherein a degree of roughness of the surface of the recording sheet is diminished due to the material such that the transferred dye is accurately fixed to the surface.
Preferably, the image transfer apparatus includes an over-coating material container, positioned upstream of the recording direction, that over-coats a material on the surface of the recording sheet subsequent to the transfer of the dye, such that the transferred dye is permanently fixed and protected on the surface.
Preferably, the recording head reciprocally records the image line by line on the surface of the recording sheet by alternately moving in the recording direction prior to the intermittant movement and opposite the recording direction subsequent to the intermittant movement.
An image transfer apparatus according to the present invention comprises an ink transfer unit that includes a layer of micro-capsules containing dye, each micro-capsule disposed in the layer of micro-capsules exhibits a temperature/pressure characteristic such that, when each micro-capsule is squashed under a corresponding predetermined pressure at a corresponding predetermined temperature, the dye seeps from the squashed micro-capsule and transfers to a surface of a recording sheet. A pressure and heat application unit is also included that applies localized the corresponding pressure and selectively localized predetermined heat to the micro-capsule layer, the predetermined heat includes heating to the corresponding predetermined temperature. A pre-coating unit that pre-coats a material on the surface of the recording sheet line by line prior to the transfer of the seeped dye is also included, wherein a degree of roughness of the surface of the recording sheet is diminished due to the material, such that the transferred dye is accurately fixed to the surface as the image.